HFU HF Underground
Technical Topics => Equipment => Topic started by: East Troy Don on August 21, 2018, 0114 UTC
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I currently run my Grundig 750 with an Alpha Delta SWL Sloper positioned from approximately 90 degrees to 270 degrees. I recently purchased a FRG-7700 and would like to run the Yaesu thru a secondary antenna positioned 90 degrees perpendicular to the Sloper (0 to 180 degrees). I have 2 questions: Can I run both antennas off the same 25 foot mast and (2) will I run the risk of signal cancellation due to the proximity of the radiating elements?
Ok, maybe a third question....would I be better off using a vertical for the FRG at the top of the mast?
I appreciate any help on this, everyone.
Thanks,
Don
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Try them all, add a vertical to the mast as well as the other sloper or whatever it is you intend to add. I'd also have some antenna switching capabilities too. By shunt feeding you can extract rf from the mast itself.
http://www.qsl.net/w9rb/webdoc9.htm
http://www.vias.org/radioanteng/radio_antenna_engineering_02_03_04.html
As to signal cancellation, the conditions would have to be ideal, meaning you will likely never find them. Something to consider however is the fact that antennas typically reradiate 2/3 of the received signal, only 1/3 of the received energy gets down the line to your rx. If you have more antennas nearby, their reradiations may increase overall rf extraction. This is why yagi and other beams work.
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Try them all, add a vertical to the mast as well as the other sloper or whatever it is you intend to add. I'd also have some antenna switching capabilities too.
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Be sure to provide proper lightning protection and grounding.
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Very helpful stuff, guys - Mucho appreciado!
Don